Results 1 to 10 of about 50,097 (222)

X-ray Eclipses of Active Galactic Nuclei [PDF]

The Astrophysical Journal, 2017
X-ray variation is a ubiquitous feature of active galactic nuclei (AGNs), however, its origin is not well understood. In this paper, we show that the X-ray flux variations in some AGNs, and correspondingly the power spectral densities (PSDs) of the ...
Lu, Youjun, Yu, Qingjuan, Zhang, Fupeng
core   +2 more sources

X-ray Properties of Radio-Selected Dual Active Galactic Nuclei [PDF]

The Astrophysical Journal, 2019
Merger simulations predict that tidally induced gas inflows can trigger kpc-scale dual active galactic nuclei (dAGN) in heavily obscured environments. Previously with the Very Large Array, we have confirmed four dAGN with redshifts between $0.04 < z < 0 ...
Djorgovski, S . G., Fu, Hai, Gross, Arran C., Myers, A. D., Wrobel, J. M.   +4 more
core   +5 more sources

X-ray bolometric corrections for Compton-thick active galactic nuclei [PDF]

The Astrophysical Journal, 2017
We present X-ray bolometric correction factors, $\kappa_{Bol}$ ($\equiv L_{Bol}/L_X$), for Compton-thick (CT) active galactic nuclei (AGN) with the aim of testing AGN torus models, probing orientation effects, and estimating the bolometric output of the ...
Ballantyne, D. R., Baloković, M., Bauer, F. E., Boorman, P., Brandt, W. N., Brightman, M., Buchner, J., Comastri, A., Del Moro, A., Farrah, D., Gandhi, P., Harrison, F. A., Koss, M., Lanz, L., Masini, A., Ricci, C., Stern, D., Vasudevan, R., Walton, D. J.   +18 more
core   +10 more sources

Review on Active Galactic Nuclei at hard X-ray energies [PDF]

Proceedings of An INTEGRAL view of the high-energy sky (the first 10 years) - 9th INTEGRAL Workshop and celebration of the 10th anniversary of the launch — PoS(INTEGRAL 2012), 2013
Hard X-ray surveys are an important tool for the study of active galactic nuclei (AGN): they provide almost an unbiased view of absorption in the extragalactic population, allow the study of spectral features such as reflection and high energy cut-off ...
Bassani, Loredana, Bazzano, A., Bird, A. J., Landi, R., Malizia, A., Molina, M., Panessa, F., Stephen, J. B., Ubertini, P.   +8 more
core   +2 more sources

Rapid X-Ray Variability in Active Galactic Nuclei [PDF]

Symposium - International Astronomical Union, 1986
SummaryRecent EXOSAT observations of active galactic nuclei are presented. Unlike earlier X-ray satellites (all of which flew in low earth orbit), the deep orbit of EXOSAT allows long continuous observations of celestial X-ray sources, uninterrupted by earth occultation etc.
P. Barr, R. Mushotzky, P. Giommi, J. Clavel, W. Wamsteker   +4 more
openaire   +1 more source

The Lively Accretion Disk in NGC 2992. III. Tentative Evidence of Rapid Ultrafast Outflow Variability

The Astrophysical Journal, 2023
We report on the 2019 XMM-Newton+NuSTAR monitoring campaign of the Seyfert galaxy NGC 2992, observed at one of its highest flux levels in the X-rays.
Alfredo Luminari, Andrea Marinucci, Stefano Bianchi, Barbara de Marco, Chiara Feruglio, Giorgio Matt, Riccardo Middei, Emanuele Nardini, Enrico Piconcelli, Simonetta Puccetti, Francesco Tombesi   +10 more
doaj   +1 more source

Clustering of X-ray selected active galactic nuclei [PDF]

Monthly Notices of the Royal Astronomical Society, 1998
A total of 235 Active Galactic Nuclei (AGN) from two different soft X-ray surveys (the ROSAT Deep Survey -DRS- and the ROSAT International X-ray Optical Survey -RIXOS-) with redshifts between 0 and 3.5 are used to study the clustering of X-ray selected AGN and its evolution.
Carrera, Francisco J., Barcons, Xavier, Fabian, Andrew C., Hasinger, Günther, Mason, Keith O., McMahon, Richard G., Mittaz, J. P. D., Page, Matt   +7 more
openaire   +3 more sources

Narrow Fe–Kα Reverberation Mapping Unveils the Deactivated Broad-line Region in a Changing-look Active Galactic Nucleus

The Astrophysical Journal, 2023
“Changing-look active galactic nuclei” (CLAGNs) are known to change their apparent types between types 1 and 2, usually accompanied by a drastic change in their luminosity on timescales of years.
Hirofumi Noda, Taisei Mineta, Takeo Minezaki, Hiroaki Sameshima, Mitsuru Kokubo, Taiki Kawamuro, Satoshi Yamada, Takashi Horiuchi, Hironori Matsumoto, Makoto Watanabe, Kumiko Morihana, Yoichi Itoh, Koji S. Kawabata, Yasushi Fukazawa   +13 more
doaj   +1 more source

X-Ray Observations of Active Galactic Nuclei [PDF]

Symposium - International Astronomical Union, 1983
HEAO 1 A2 and Einstein SSS spectral observations of Seyfert galaxies and BL Lac objects suggest that in both cases, the X-ray emission is due to relativistic particles. The five BL Lac objects have very soft spectra and at higher energies (above 10 keV) may have hard tails.
C. Megan Urry, Richard F. Mushotzky, Allyn F. Tennant, Elihu A. Boldt, Stephen S. Holt   +4 more
openaire   +1 more source

X-Ray Variability of Active Galactic Nuclei [PDF]

Highlights of Astronomy, 1983
X-ray variability of active galactic nuclei is commonplace on scales from days to years. It also occurs, although rarely, on time scales as short as 200 seconds. Both these statements must be strongly qualified by the irregularity and insensitivity of the available observations. In the X-rays we expect that we are seeing deep within the active nucleus,
Daniel A. Schwartz, Greg Madejski, William H.-M. Ku   +2 more
openaire   +1 more source